Run java thread at specific times

Question

I have a web application that synchronizes with a central database four times per hour. The process usually takes 2 minutes. I would like to run this process as a thread a

Answer 1

You can let the Runnable schedule its "next run".

Such as,

class Task implements Runnable {
    private final ScheduledExecutorService service;

    public Task(ScheduledExecutorService service){
        this.service = service;
    }

    public void run(){
        try{
             //do stuff
        }finally{
            //Prevent this task from stalling due to RuntimeExceptions.
            long untilNextInvocation = //calculate how many ms to next launch
            service.schedule(new Task(service),untilNextInvocation,TimeUnit.MILLISECONDS);
        }
    }
}

Answer 2

TimerTask handles this case.

See schedule(TimerTask, Date)

If you don't want to have to keep scheduling the jobs, you may want to look into a job scheduling tool like Quartz.

Answer 3

Quartz would be a good fit since you're application is web-based. It will provide the fine-grained time based scheduling you need.

Quartz is a full-featured, open source job scheduling service that can be integrated with, or used along side virtually any Java EE or Java SE application - from the smallest stand-alone application to the largest e-commerce system. Quartz can be used to create simple or complex schedules for executing tens, hundreds, or even tens-of-thousands of jobs; jobs whose tasks are defined as standard Java components that may executed virtually anything you may program them to do. The Quartz Scheduler includes many enterprise-class features, such as JTA transactions and clustering.